bzoj 2733 永无岛

裸的splay启发式合并，其实就是用队列实现的暴力合并，轻松写过~
Neverland
  1 #include<iostream>
  2 #include<cstdio>
  3 #include<algorithm>
  4 #include<cstring>
  5 #include<cmath>
  6 #define maxn 200000
  7 using namespace std;
  8 
  9 int c[maxn][2];
 10 int fa[maxn],f[maxn],rank[maxn],size[maxn],q[maxn];
 11 int n,m,num,p;
 12 
 13 inline int find(int i)
 14 {
 15         return (!f[i])?i:f[i]=find(f[i]);
 16 }
 17 
 18 inline void update(int x)
 19 {
 20         if (!x) return ;
 21         size[x]=size[c[x][0]]+size[c[x][1]]+1;
 22 }
 23 
 24 inline void rotate(int x)
 25 {
 26         int y=fa[x],z=fa[y];
 27         int p=(c[y][1]==x),q=p^1;
 28         if (fa[y]) 
 29                 if (c[z][0]==y) c[z][0]=x; else c[z][1]=x;
 30         fa[x]=z; fa[y]=x; fa[c[x][q]]=y;
 31         c[y][p]=c[x][q]; c[x][q]=y;
 32         update(y);
 33 }
 34 
 35 inline void splay(int x)
 36 {
 37         while (fa[x])
 38         {
 39                 int y=fa[x],z=fa[y];
 40                 if (fa[y])
 41                         if ((c[y][0]==x)xor(c[z][0]==y)) rotate(x); else rotate(y);
 42                 rotate(x);
 43         }
 44         update(x);
 45 }
 46 
 47 inline void insert(int &t,int anc,int x)
 48 {
 49         if (t==0) 
 50         {
 51                 t=x;
 52                 fa[x]=anc;
 53                 size[x]=1;
 54                 splay(x);
 55                 return;
 56         }
 57         if (rank[x]<=rank[t]) insert(c[t][0],t,x);
 58         else insert(c[t][1],t,x);
 59         update(t);
 60 }
 61 
 62 inline void merge(int x,int y)
 63 {
 64         if (size[x]>size[y]) swap(x,y);
 65         splay(x); splay(y);
 66         int head=0,tail=1;
 67         q[0]=y; q[1]=x; 
 68         while (head<tail)
 69         {
 70                 int now=q[++head];
 71                 if (c[now][0]) q[++tail]=c[now][0];
 72                 if (c[now][1]) q[++tail]=c[now][1];
 73                 c[now][0]=c[now][1]=0;
 74                 insert(q[head-1],0,now);
 75         }
 76         //splay(x);
 77 }
 78 
 79 inline int search(int t,int k)
 80 {
 81         if (k>size[t]) return -1;
 82         if (k==size[c[t][0]]+1) return t;
 83         if (k<size[c[t][0]]+1) return search(c[t][0],k);
 84         if (k>size[c[t][0]]+1) return search(c[t][1],k-size[c[t][0]]-1);
 85 }
 86 
 87 int main()
 88 {
 89         //freopen("never.in","r",stdin);
 90         scanf("%d %d",&n,&m);
 91         for (int i=1;i<=n;i++) scanf("%d",&rank[i]),size[i]=1;
 92         int x,y;
 93         for (int i=1;i<=m;i++)
 94         {
 95                 scanf("%d %d",&x,&y);
 96                 if (find(x)!=find(y))
 97                 {
 98                         merge(x,y);
 99                         f[find(x)]=find(y);
100                 }
101         }
102         //for (int i=0;i<=n;i++) cout<<i<<' '<<fa[i]<<' '<<c[i][0]<<' '<<c[i][1]<<' '<<size[i]<<endl;
103         scanf("%d\n",&p);
104         char sign;
105         for (int i=1;i<=p;i++)
106         {
107                 scanf("%c %d %d\n",&sign,&x,&y);
108                 //cout<<sign<<endl;
109                 if (sign=='B') 
110                 {
111                         if (find(x)!=find(y))
112                         {
113                                 merge(x,y);
114                                 f[find(x)]=find(y);
115                         }
116                 }
117                 else
118                 {
119                         splay(x);
120                         int ans=search(x,y);
121                         printf("%d\n",ans);
122                 }
123         }
124         return 0;
125 }
posted @ 2013-03-28 22:52 Zig_zag 阅读(211) 评论(0) 编辑收藏举报
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